إِيَّاكَ

إِيَّاكَ is a phrase (شِبْهُ الجُمْلَةِ), a compound consisting of an objective particle and an accusative noun

Particle/objective pronounNounParticle
اسْمٌحَرْفٌ
CompoundObjective case of pronounSuffix
You aloneإِيَّكَ=كَ+إِيَّا
You aloneYoualone
Surah/Below is the only verse in the holy Quran containing the 2 occurrences of the compoundإِيَّكَ
Verse
1-5Only You alone we worship and only You alone we ask for helpإِيَّكَ نَعْبُدُ وَإِيَّكَ نَسْتَعِيْنُ